The armchair design is a continuation of the previous model, with a link provided in the description part. In this design, sewing is first added to the model, and then the seat legs are modeled.
The "Proboolean" command should be used sparingly in designs. But when using this tool, it is important to refine our model to ensure correct design typology.
Therefore, connecting the two parts of the seat base with the help of "Attach" and "target weld" is a good solution that can be used in other models to connect the points two by two.
"TurboSmooth, similar to Open Subdiv, assists in creating a smoother design."
Therefore, to control the working corners, it is better to add edges so that the model is flexible and not too soft.
link:
https://youtu.be/vpIT8SexVN4